Repeatedly saying the word "me," which activates some of the muscles involved in a smile, puts people in a better mood than repeatedly saying "you," which activates muscles involved in a frown. this best illustrates

This best illustrates " facial feedback effect".

Facial feedback theory expresses that facial development can impact enthusiastic and emotional experience. For instance, a person who is compelled to keep smiling amid an event will finally come to discover the occasion a pleasant one. Charles Darwin was among the first to recommend that physiological changes caused by a feeling directly affected, as opposed to being only the outcome of that feeling.